Brake FAQ and mythbusting

Car brake FAQ - with focus on VW TDI but applicable to all cars
Back to 1000 answered questions: turbodiesel FAQ and general "how to" index

Introduction

This article answers a lot basic information and busts some myths about braking. It is applicable to all street driven cars but written with a street driven car in mind. There are marketing ploys and honest misinformation that is repeated on internet forums, this article will dispel some of them. Also, do you really want a big brake upgrade? Many "racing" upgrades like race brakes are of no performance benefit on a street car and may even make braking worse, see below for an explanation.

What exactly do I mean by a street driven car? On the street, you will make at most, two panic (0-60 mph) stops in a row during normal driving. Even stop-go traffic would be considered light braking since the speeds are not very high and you're not slamming on the brakes. Track use or heavy, repeated braking is not normal street driving, especially in a VW TDI, that's track use. A sports car speeding through a canyon or a truck towing a boat down a mountain is also not normal street driving. This page also assumes "everything else being equal". A base economy car is not designed to withstand the same type of "normal" driving that a sports car should be, nor is a car with 200,000 miles on the original suspension the same as a brand new car's or the same car with an aftermarket suspension.

How to change your VW TDI brakes
Mk3 Jetta or Passat front brake job - rear Passat disk brakes - rear Jetta drum brakes
Mk4 Jetta, New Beetle, Golf brake job

Contents
Common complaints
Brake pads and rotors - increasing performance
Busting myths about big brake kits
External links and scanned magazine articles about braking

Common complaints

Brakes are squealing:
This is a common complaint on VWs. All VW mk4 and newer with ABS (All north American cars) use Electronic Brake Distribution, EBD. Under light braking, the rears actuate first and harder than the front. This minimizes dive and is why your rear brakes wear out first. As braking becomes harder, EBD changes the bias to the fronts. In addition, the brake rotor is designed to be almost worn out by the time the pad is worn. Always check rotor thickness against the spec in your factory service manual when servicing the brakes. Although most VW have brake pad wear sensors on the front, check pad thickness as well.

Brake noise is normally caused by a combination of rotors, cold pads, pad shape, and rotor/pad material. Sometimes it's a whisping or grinding noise and sometimes it causes vibration which causes a high pitched screeching noise. Because the properties of pads and rotors change slightly when heated, as you drive, they warm up and sometimes the squeal goes away. It's normal for some performance pads to screech when cold as well. If you are on stock VW pads and rotors, try an occasional hard brake to change the bias to the front and heat up/wear down the front pads. If you are on performance pads, try less aggressive pads. Some cars use shims or anti-squeal grease (not on the friction surfaces!) to quiet the brakes. You may also notice rust on the rotor faces of a car that isn't driven often. This may cause some noise but will quickly wear off with use.

Brake pedal isn't firm or no braking authority:
In an emergency situation with no brakes, your priorities should be to keep control of the car, pump the brakes and brake as needed, steer the car towards a safe spot, and apply the parking brake to slow down. You can try downshifting to use engine braking to slow down the car as well. Do not get distracted from driving when trying to troubleshoot a braking problem, your first priority is to keep control of the car! If you see leaking brake fluid around the wheels or in the footwell near the brake pedal or master cylinder, have the car repaired before driving!

If you have no braking authority and the pedal goes straight to the floor or almost to the floor, the car has lost brake fluid pressure. Pump the brakes and if either the front or rear brake fluid circuit is still good, you should get some braking action on the good circuit. A common cause of this is a bad brake line near the caliper. Another possible cause is air contamination. If you are in a racing environment, the brakes were overworked and you probably overheated the pads/rotors or boiled the brake fluid.

If you have no braking authority but you feel resistance in the pedal, pump the brakes and try to build up pressure. Possible causes are bad caliper, master cylinder, or brake pads. If the brake slowly goes to the floor, this is normally a bad master cylinder. Look under the dashboard and at the engine bay firewall for leaking fluid or stains. If the brake pedal feels very stiff and hard but you still have braking authority, just press very hard on the pedal. This is normally a faulty brake booster.

Shaking through the brake pedal or vibration when you press the brake pedal:
Something is vibrating and the force is transmitted through the brake pedal. If you are driving very hard or slamming on the brakes, it could be the ABS pump cycling. You can normally hear the pump humming. Vibration could be the pads, caliper, or hub but it's normally a rotor issue. Check for uneven brake deposits (splotches on the rotor face), rotor runout, and hub runout. Take a runout reading with the rotor bolted to the hub. If it needs to be turned (machined on a brake lathe), that's fine as long as it doesn't go below minimum rotor thickness and specs. Because VW rotors are so cheap, it may be better to just buy new rotors. If it's due to a bad hub, you must have the rotor machined on the car or replace the hub. This costs more but a flat rotor on a bad hub will not solve vibration issues.

Brakes pads and rotors - increasing braking performance

Tires:
Sticky tires should be the first step to upgrading braking force or handing in any way. Any increase in braking force is pointless if you do not have enough tire grip to hold more force. Otherwise, it will only result in the tires locking up and skidding, (with non ABS cars) increasing braking distance through a loss of control. Again, you can never stop faster than the tires will allow (unless you have reverse thrusters or the optional drag parachute)!

A tire with a more aggressive tread compound/pattern will increase how much braking force can be applied to the ground to stop the car. Don't buy the super cheap tires: they tend to be louder and constructed less sturdy - you get what you pay for! Your car and your safety are riding on the tires, so before you upgrade brakes, make sure that your tires can handle it. Use a summer tire and if you live in an area which requires you to use winter tires, switch over when needed. All season tires have average performance in summer/winter but summer tires will have better performance, everything else being equal. You can also choose a wider tire on a wider wheel and adjust tire air pressure lower. This increases the size and changes the shape of the tire footprint. The drawback is that lower air pressure and wider and more aggressive tires will reduce fuel economy. Because of this, it's best to get a tire that can handle all of the braking force that your ideal brake system will have. For many people, this is the stock brake setup. Some people will choose a big brake kit, see 1000q: mk3 BB kit or 1000q: mk4 BB kit for a chart of available big brake kits and installation procedures.

As a rough theory, each tire should reach the limit of traction at about the same time to maximize straight line braking. This takes advantage of all available traction on all 4 tires. (To be specific, the stock rear brakes sacrifice some braking performance for better directional control. Skidding rear tires can easily result in loss of control. This is also to account for differences in car weight and balance from different fuel and cargo loads, a shifting center of gravity, front/rear brake bias, and changes in tire/brake setups.) Read the scanned articles below if you don't believe me. In one article, every tested car had "brakes strong enough for the [ABS] system to hold its tires on the verge of lockup for at least one full stop." The stock Passat that was tested even had consistent braking over 25 panic stops from 70-0 mph. Maybe there is something to being tuned for the Autobahn! The Passat brakes were not overloaded for it's setup but this doesn't mean that brake performance couldn't be better, just that the brakes are not the limiting factor. In this specific case, I believe that you could increase tire grip until the brakes or another component became the limiting factor in stopping performance.

Suspension:
The suspension is another major factor in braking performance. A worn suspension changes the way the brakes are supposed to behave. VW TDI suspensions are soft and tend to be worn out by 100,000 miles. New struts, strut bearings, mount, control arm bushings, and anti-sway bar bushings in the front will do a lot to restore the handling and braking bias on your VW. The rears need new mounts and struts. If your car feels like a heaving dinghy in a storm then a big brake kit won't do much. Also note that many brake bias valves on the rear beam axle of mk3 VW are rusted and may not work. It's supposed to change the bias as the car heaves forward during braking. Don't adjust bias by yourself, take it to a VW specialist who has the tools to calibrate it. All mk4 and newer use EBD (see above).

Brake Pad choice:
There are too many brands to list, but I suggest a normal street pad for street driving. Most TDI drivers would prefer an OEM-level pad since a normal level pad will make less noise and generally less dust than more aggressive performance pads. For some reason, some aggressive pads dust less due to composition, it varies by brand and model. In general, the stock VW metallic pads last longer than organic pads but can be noisier. See below for an explanation of ceramic pads.

Although more aggressive performance pads can bite harder (due to friction coefficient) and withstand higher temperatures, this normally doesn't translate into shorter stopping distances on the street. It will change bite and feel but in most cars, the pad is not the limiting factor in stopping. In other words, pads on an otherwise stock car may cause you to feel the brakes are better because they bite harder with less brake pedal travel. A higher friction pad can exert the same torque on the rotor with less pedal force but this initial bite does not necessarily stop the car in a shorter distance. With a less aggressive pad, you just have to press harder on the brake pedal to exert the same torque on the rotor. If you've just read this and don't believe me, read the scanned article at the bottom "Pulp Friction". Again, this article is written with a focus on street use, not track use. For track use you definitely need performance high temp pads due to the high temperatures seen with track use.

Good braking feel is a combination of pedal resistance and travel, different pads change this. You might like how aggressive pads feel, so before buying a big brake kit, try changing the brake pads. If you have cheap aftermarket pads, this could go a long way toward improving braking feel. This shouldn't make the car stop shorter but it should bite harder with less pedal travel and change braking feel. Some aggressive pads that work well for street driving are the Hawk HPS or Axxis metal masters. There are too may brands and types to list, these are just two.

Track or race brake pads:
Never use "race" or "track" high temperature pads unless you are on a track. Race pads are designed only for track use and need to be hot to function well. In addition, the brake dust can become hard if it gets wet and isn't washed off which can damage your wheel's finish. I don't like pads advertised for both track and street use like the Hawk HP plus. They stop fine for street use but produce more unnecessary dust and squealing than a street only pad with no increase in street performance. These levels of pads are best if you want to track your car with the same pads that you drove in on or for autocross. However, it's still best to use a separate street pad and put in a track pad once you are at the track. You wouldn't use winter tires on a road course either - match the car setup to the intended use!

Brake bedding:
This is a way of breaking in pad and rotor surfaces to maximize braking force. Although following a strict technique is not mandatory for street use, it is recommended by all brake makers. You probably won't find the technique in your owner's manual so consult your brake manufacturer for the specific procedure. The basic idea is to warm up the brakes and then transfer an initial layer of pad material onto the rotor and heat relax it. This increases braking performance and life.

After the brakes are properly bedded, the pads contact a thin layer of transferred brake pad material instead of the rough surface of the rotor. This adhesion between the pad and transferred material on the rotor is a major source of braking force in addition to the abrasion of a pad scraping the rotor. You can read more about this at the Stoptech site's notes on bedding. As a side note, new tires also have a slippery surface that has to be worn away with normal driving, so new brakes and new tires = less braking force.

OEM vs. aftermarket rotors, cryo treating, zinc or cadmium coating:
OEM rotors are made to a certain standard. Some aftermarket rotors are better, some are worse. Some ebay rotors use low quality iron and won't work well compared to high quality rotors. The difference is weight, balance, machining, longevity, and resistance to cracking. Because of this, I recommend name brand or OEM rotors. I would also avoid ebay rotors in general since they could be counterfeit.

Cryo treating does nothing on a cast iron rotor because it's exposed to wild heating and cooling cycles. It's a marketing ploy. Zinc or cadmium coatings help reduce rust on the rotor and this can improve the appearance of the rotor.

Ceramic carbon rotors and pads:
Ceramic carbon composite rotors are rotors made out of a ceramic resin material. Don't confuse them with ceramic pads or a "coating". They are carbon fibers bonded with resin which is baked into silicon carbide. The silicon carbide is where the carbon or ceramic name comes from. Pictured below is the ceramic carbon material.

You might hear of ceramic coatings on iron rotors, these are marketing ploys. Real ceramic rotors are very expensive: it's an $8,000+ option on a Porsche and a $30,000 option on some high end luxury cars. Replacement Porsche rotors are about $5,500 each! They don't make the car stop shorter on the street compared to a cast iron rotor but have other advantages for street use. For $8,000, you get much longer life, less brake dust, 50% less weight (less unsprung weight increases handling), and they look really cool. Porsche estimates that their PCCB rotors could last over 150,000 miles with normal street driving but to expect about 1500 track miles. While they're on the second generation of rotors, there's no warranty on the rotors when used with aftermarket pads and there are still complaints of cracks.

Multiplied by 4 rotors, you can lose an average of 38 lbs of unsprung weight which is pretty significant! In theory, this should result in shorter stopping and greater fuel economy due to less rotating mass. In reality, the difference is well within the normal variations in fuel economy, road/tire surface, driver behavior, etc., so don't expect to see any difference in fuel economy. For track use, the advantages of ceramic rotors are more apparent. The reduction in unsprung weight becomes more noticeable and they are more resistant to warping or heat levels seen at the track. Combined with their high price, you won't see them on cheap street cars anytime soon.

Although the huge weight reduction is great, my opinion is that PCCB isn't worth it since most drivers will never notice any difference except better ride comfort from the weight loss. For 99% of drivers, spending that money on driving lessons will give far better results than fancy brakes.

Ceramic pads are sometimes equipped on factory stock cars. The problem is that some aftermarket pads use these terms as a marketing ploy. If a single carbon ceramic rotor costs over $5,500, how can you can get the same exact material in a brake pad for $30 per pad? True ceramic pads are normally a metal matrix with ceramic particles and copper and other fibers. In theory, they should perform better but the limiting factor is often the other brake setup components. Again, this can change brake feel but stopping distances are often unchanged. On the track, they are supposed to work well across a wider range of temperatures but this goes back to the ideal of having separate pads for street vs. track. So far, the best advantage of switching to ceramic pads is that they dust less. Since they work as well as metal or organic pads, they are a good choice, just don't think you are getting the $5,500 rotor material in your brake pad.

Drilled and slotted rotors:
I recommend blank faced rotors for all cars, even ones that see the track. They cost less, perform better, and are less likely to warp/crack.

I do not recommend slotted or drilled rotors because they don't increase braking performance. If you want to improve the look of the rotor, slotted rotors are less susceptible to cracking than drilled. They can change brake feel but it won't make the car stop shorter. Slotted rotors can clean overheated and glazed brake pads but this is not be a factor for street only cars and is caused by improper pads for the situation. (On track cars, overheated pads are more common and could be helpful). Slotted rotors also eat up the pads more than necessary to stop the car. For more on this, see the section below "the truth about big brake kits for the street", and read the scanned articles below.

The holes in rotors were originally used to vent gas build up from hot brake pads during racing, a problem that you won't see with the materials used in modern, broken-in brake pads. Testing shows that drilled rotors actually make the rotor heat up more than if it were solid! I repeat, drilled rotors run hotter than an identical non drilled rotor. This heat is then transferred to the caliper/pad/hub/wheel bearings/brake fluid with a negative effect. If you want to reduce the rotating or unsprung mass of the brake, it's better to use a smaller 2 piece rotor than a larger drilled rotor.

Localized uneven heating of the material along the edge of the holes vs. the rest of the rotor causes cracking from thermal stress. Although the holes might be chamfered (edge of the hole is smoothed) on the outer rotor face, they are not chamfered on the inner face. If someone says to buy only drilled rotors which have the holes cast, this is also false. All holes in rotors are CNC drilled and machined. There are rumors of Porsche casting the holes but this is a myth. If they did, they are the only manufacturer to make their own brakes like this. Nobody has ever proved it and there is a reward for proving that Porsche casts the holes. To this day, it's unclaimed. In addition, not only would casting and precisely machining the small holes be difficult and expensive (with a price not reflected in the replacement rotor cost), machining the holes after casting would reduce any benefit.

The argument that they are for racing is also false - no aftermarket big brake kit vendor recommends a drilled rotor for heavy track use. Go to a race track and see what the race cars are using. Depending on what type of "track" you see, you might see a car with drilled rotors but a race team can afford to go through a few sets each season and they might have certain parts on their car due to sponsorship or regulations. If drilled rotors had a worthwhile benefit, you would expect to see them on the landing gear of jet aircraft or locomotive brakes but they use blank faced rotors too. If your rotors saw extreme heat as in just came off the track, not just came off the highway, keep driving for a bit to get some cooling air flow. This will help avoid slow cooling and warping.

If your car sees track use, you should be using brake ducting to cool the brakes (and using the correct pad for track use), not drilling holes in rotors. Pictured below is an example of brake ducting. Wheel design can also make a difference in brake cooling and air extraction. Use temperature sensitive paint to test rotor temperatures to determine ducting and brake system needs. Don't bother using an infrared heat gun unless you can aim it out the window while braking...my aim is no good!

What direction should the drill holes or exterior slots point?
It doesn't matter if the holes/slots point forward or backwards, it's all the same. Depending on the manufacturer, the holes/slots may point front/back, straight/curved, it does not make a difference. Don't confuse the slots cut into the rotor face with the internal vanes because vane direction does matter!

What direction should the internal vanes point?
Virtually all modern cars use vented front rotors. Most OEM parts use straight vanes so they can use reduce manufacturing costs and use the same brake on both left and right sides. Better rotors use internal directional vanes for cooling. Unlike drilled rotors, directional vanes do help brake cooling. Remember, the drilled holes or slots on the outside face of the rotor are not directional but the internal vanes sandwiched between the rotor faces must always vent air out. In other words, accounting for the direction of rotation, the vanes should always push air out from the hub and "lean" towards the rear of the car. Again, brake ducting is a major factor in cooling brakes so consider that as well. Below is an example of internal vanes direction vs. external slot direction.

If the vanes are straight, they are omni directional and can be mounted on either the driver or pass side.

Why you may want aluminum hat or 2 piece rotors:
If you are serious about reducing unsprung weight, I recommend 2 piece rotors or floating/hat rotors because they are much more cost effective than carbon ceramic rotors. I doubt anyone is spending $20,000 for CC brakes for their street driven VW! These are rotors with a ring shaped braking surface bolted or pinned to an aluminum "hat" hub. It is more resistant to warping than a 1 piece rotor because the hat can expand and contract independently of the rotor and is much lighter due to the aluminum hat. Bolted rotors are much quieter than pinned/floating rotors but don't allow for as much expansion during heavy racing use. Some pinned rotors use belleville spring washers or spring clips to reduce noise but I recommend bolted rotors for street use. Even though pinned rotors for street cars come with springs or clips, some just make a lot of noise that is not acceptable on a street car. If you are heavily racing your car, you should be using pinned floating rotors since they allow for greater expansion between dissimilar metals.

Reducing rotor weight will noticeably increase comfort/handling and positively effect mileage, acceleration, and braking performance because you are reducing rotating mass and unsprung weight. The only negative is the high cost, as much as three to four times as much for the initial setup. However, once the rotor face is worn out, you can reuse the hat with a replacement braking surface so the overall cost isn't that bad.

Here is an example of a Wilwood bolted 2 piece rotor. The bolts are safety wired in. The black piece is the aluminum hat. Even though it's larger in diameter than the cast iron rotor on the right, it's about 5 lbs lighter and cools better due to the internal vane structure. While lighter wheels are also a priority for reducing unsprung weight, wheels aren't a replacement item.

Stainless steel braided brake lines:
These can add braking feel on the track but can be more prone to failure than rubber brake lines. The reason stainless steel braided brake lines are used in a racing environment is because it protects the line from track debris and it helps control line expansion. Although this firms up pedal feel, it will not make your car stop any shorter. I recommend leaving the stock brake lines alone on a street car because they should last the life of the car.

Improper installation, twisting, or dirt getting into the steel braids will also damage a SS brake line. SS lines tend to have a slightly shorter life overall compared to rubber lines. A track car which has the brake lines changed every 2 years and doesn't see a lot of mileage won't see the limit of a SS line but a 15 year old street car with 300,000 miles might. Broken metal braids can chafe the internal tubing and can cause a line break and loss of braking force. Plastic coatings or covers on the braid can help prevent chafing. Always use name brand stainless steel brake lines and make sure the braids or lines are not twisted, and never ever buy ebay cheapo brake lines. Many of those are known to be non-DOT approved (or counterfeit) and prone to failure. A failure may be sudden and will cause you to lose braking force, probably resulting in an accident. Your safety is not worth buying cheap brake lines. Stoptech, goodrich, willwood, brembo, baer, ATE, or other brand name SS braided brake lines are more reliable than cheapo brake lines. Don't buy these lines off ebay because they could be counterfeit items. For the US, brake lines must be tested to DOT FVMSS 106.

Why you need to change your brake fluid:
You have to change your brake fluid every 2 years or as needed because it breaks down with heat, age, and absorbs water. Modern VWs use DOT 4 fluid. Always use freshly opened bottles of fluid instead of old bottles because it may have already absorbed moisture from the air in the bottle! Moisture can also condense in lines and calipers. DOT 3, 4 brake fluid is designed to absorb water so that it doesn't pool in the low spots and cause rust. If water in the brake fluid gets too hot, it can actually boil and produce an air bubble. This can use poor brake feel because the air bubble absorbs the hydraulic pressure instead of being transmitted to the brakes. Fresh brake fluid reduces water content. If you are using the car on the track, you should be using racing brake fluid. Not using race brake fluid and a brake setup sufficient for a racing environment can result in total loss of braking authority!

The truth about big brake kits for the street

For street use, some cars can stop shorter from adding big brake kit but some cars will actually lose braking performance! The engineers who designed your car made the brake system according to the day-day changing weight and balance of the car (fuel load, passengers and cargo, etc), suspension settings, and the stock tires. Again, as a rough theory, each tire should reach the limit of traction at about the same time to maximize straight line braking. This takes advantage of all available traction on all 4 tires. (To be specific, the stock rear brakes sacrifice some braking performance for better directional control. Skidding rear tires can easily result in loss of control. This is also to account for differences in car weight and balance from different fuel and cargo loads, a shifting center of gravity, front/rear brake bias, and changes in tire/brake setups. With all mk4 and newer VW, the electronic brake distribution in the ABS actually applies the rear brakes first under light braking.)

Changing any brake/tire/suspension component from stock will change how the brakes behave during braking. For example, a big brake kit on the front will increase braking at the front tire but this bias and weight shift doesn't let you take advantage of unrealized grip at the rear tires. This could result in longer stopping distances. In some cases, a medium big brake kit will give better braking than the large big brake kit just due to balance! All good brake kits increase braking torque without negatively effecting the bias. Good brake kits should keep about stock pedal travel and be matched to the brake master cylinder. Combined with how well the engineers designed the stock braking system and considering economic considerations with a mass produced car, you might gain performance, you might lose performance with a kit. A sports car might be already tuned from the factory for optimum braking performance. A softly tuned car might have considerable room for improvement over the factory setup. This doesn't mean that braking feel is unchanged because like brake pads, changing the brake setup changes pedal feel, modulation, travel, and lowers rotor/caliper/pad/hub temperatures. Unfortunately, brake feel does not equal shorter braking distance - again, the weight shift, brake bias, etc., are effected by changing the brake setup.

Does this mean that big brake kits are a scam? Absolutely not! Stickier tires, suspension changes, adjustments in the weight and balance of the car, all change the behavior of the braking setup. Some cars have smaller rotors which are undersized. As a car ages or as you replace worn out parts, you can take advantage of a big brake kit. If you use the car on a track, a big brake kit is actually needed on most cars! A big brake kit has greater rotor and pad mass to absorb the additional heat, pad compounds that can handle high heat, etc. VW brakes are fine for street/light autocross, but heat up pretty quickly when really pushed. Again, this article is written with a focus on street use. So would your car benefit from a big brake kit? It changes by car model, individual car setup, and your intended use, so the correct answer is "it depends".

For example, Eurocar did a braking test of the New Beetle. After 5 full back to back 60-0 mph stops, the brakes were overheated. Switching to the mk4 Golf R32 brakes kept the brakes cool after many stops. Brake ducting can help but if you have 2.slow or TDI engine New Beetle, then a big brake kit is mandatory if you want to track the car. But if you are making 5 full panic stops in a row during normal street driving, the problem is driver behavior. Again, this doesn't include towing (the New Beetle wasn't designed to tow heavy loads) or driving down long downgrades (you should downshift for engine braking), or 5 deer jumping out on the highway in a row (unlikely), etc. See 1000q: mk3 big brake upgrade chart or 1000q: mark iv big brake upgrade charts to see big brake kits for your VW, both OEM and aftermarket.

To put kits in perspective for the street, let's say a well designed big brake kit can reduce panic braking (single hard stop, not repeated stops) distances by 5 feet. This would be very good for a big brake kit on an otherwise stock car/stock tires, etc. 5 feet could be the difference between an accident and avoiding an accident.

But for street driving, increasing the distance between traffic and driver behavior, everything else being equal, are the primary factors in avoiding accidents. More time and distance between cars also reduces stone chips, driver stress, and increases mileage because you don't have to tap the brakes as often. In addition, driver behavior during an emergency braking situation is not to immediately slam on maximum braking. Most drivers will apply the brakes medium, then think "Oh sho!T, this guy means it!", then slam on the brakes. In this case, a big brake kit won't save you if you weren't braking hard in the first place. And if you just stopped that hard, the guy behind you couldn't and just hit you from behind! If you skipped the first section where tires are often the limiting factor, read it again and the scanned articles below. The mk5 Passat made 25 panic stops from 70-0 with consistent performance. Again, this doesn't mean that brake performance couldn't be improved, it's just that the tires were the limiting factor, not the brakes.

Back to 1000q: turbodiesel FAQ and "how to" index

External links and Additional reading

http://www.sportcompactcarweb.com/tech/0710_sccp_point_brake_tech/index.html - case where a well designed big brake kit on a modified car resulted in worse braking

http://www.zeckhausen.com/Testing_Brakes.htm - test between stock, stock plus, and aftermarket brakes

http://www.europeancarweb.com/tech/0402ec_autotech_r32_brake_conversion/index.html - conversion of stock New Beetle brakes to Golf R32 Brakes and test

http://forums.corvetteforum.com/showthread.php?t=1034158 - compilation of posts about brakes from a Corvette forum

http://corner-carvers.com/forums/showthread.php?t=21273 - if you can prove Porsche casts the holes in the rotor, this guy has a reward for you

Pulp Friction - 6 thumbnails, click for larger view - scanned from Grassroots Motorsports and mkiv.com

The Power To Stop - scanned from Car and Driver Aug 2008